SEVASTOPOL, August 18. /ITAR-TASS/. Ukrainian President Petro Poroshenko has been warned he must give up ownership of a shipyard on the Crimean peninsula if the firm wanted continued orders from Russia's military, a regional official said on Monday.

Poroshenko's Sevastopol Marine Plant is located in the Russian federal city from which the company takes its name, Russian-speaking and long-standing home base of Russia's Black Sea Fleet naval fleet. He has been told to give it up, or face the consequences.

"We're not filling the plant's capacities at present due to the problem with the owner, which is being settled at government level. Once it's resolved, the shipyard will begin to receive defence and civilian orders," said acting Sevastopol governor Oleg Menyailo, adding that he believed the company would regain its previous status.

Poroshenko has also been told to relinquish his business interests in accordance with international norms and the EU leadership had to nudge the Ukrainian leader towards this decision, Menyailo added.

Poroshenko is among Ukrainian business people having property in the city, required to re-register interests under Russian laws and being warned they would have no prospects if they continued to operate under Ukrainian jurisdiction.

"Initially, we offered all Ukrainian company owners two options: They either re-register or operate as a foreign resident in Russia's legal space," Menyailo said, noting that such options were not imposed on "vital energy, communication and transport facilities".

Inquiries are also under way into Avlita port stevedoring firm owned by Ukrainian oligarch Rinat Akhmetov and Balaklava mineral ore company, part of entrepreneur Vadim Novinsky's Smart holding, Menyailo said, adding that Novinsky had been blamed for major violations of environmental regulations.